The Knees* (As featured in Moto magazine)
So for part 2 of the body series (You can view part 1- the ankles here) we discuss the structure of the knee and proven ways to prevent injury & improve your performance. If you're an action sports athlete or specifically a motocross rider, then read on! (Previously featured in Moto magazine)
Motocross is one of the most physically demanding sports in the world which impacts a lot on the body and the knees which are a crucial part of the human suspension system providing both shock absorption and stability of the body's weight & all the additional forces that are placed through it. They take a huge amount of abuse being dragged around the corners, taking knocks and bangs, gripping the seat and absorbing & pre-loading the bumps & jumps
Bikes often get priority when it comes to maintenance, for instance the front and rear suspension are protected by fork and mudguards to deflect and defend any damage caused by impact of stones, rocks or other bikes and the metal is relatively strong anyway, however when it comes to the knees (the human suspension system) which are subject to the same threats, protection is rarely worn. The difference being the components of the knee cannot simply be replaced.
The knee is the joint between the femur (thigh bone), Tibia (shin bone) and the fibula (adjacent to the tibia) and is made of multiple layers of muscle, cartilage, nerves, blood vessels and bone but what gives the rigidity and overall structure are the 4 key ligaments. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are located within the knee connecting the femur and tibia to limit rotation, forward, and backward motion of the tibia, and running along the inside and outside of the knee are the medial collateral ligament (MCL) and lateral collateral ligament (LCL). The MCL connects the femur to the tibia and the LCL connects the femur to the fibula which limits the sideways motion of the knee.
The nerves within the knee can be as small as hair strands! They are effectively wires that send signals to the muscles from the brain telling them when to contract and relax. The muscles control movement which is mega important- we can train these to be stronger and to last longer (endurance).
Cartilage lines the bones, absorbing shock and cushioning the joint to prevent friction of the bones.
Did you know?
Ligaments are similar to elastic bands, once a minor tear becomes present the elastic properties lessen and the structure diminishes leaving the ligament in a weakened and stretched state. It's easy to do this too when the diameter of the average knee ligament size is considered 3mm-13mm.
Symptoms of injury
Cartilage damage pain is usually felt at a particular knee angle and will feel as if something is being pinched (commonly at the front of the knee below the knee cap).
Signs of ligament damage include pain, swelling, bruising around the area and tenderness however the biggest sign is the knee 'giving way', particularly when going up or down stairs. There are different levels of severity for sprains ranging from a few fibres torn to a complete rupture (when one end is no longer connected to the other).
Minor sprains can be easily treated by carefully prescribed rehab exercises specific to you and your injury, however when a ligament is completely ruptured it will often require surgery and the operation isn't nice! It's invasive and the ACL reconstruction for example takes over 3 months for the graft to fully form followed by extensive strengthening rehab if you want the graft to work! That's nearly a full season off the bike!
'There's no solution to a problem like a preventative measure!'
The mechanical solution part 1.
1) Protect yourself before you Wreck yourself
It's not all doom and gloom, when injuries happen get them checked out before you cause further damage, but if you haven't injured them yet do everything in your power to keep it that way! The easiest way to protect yourself is to invest in is a good set of knee braces. These have been extensively researched and designed to provide protection and maximize performance. Braces are designed to protect and dissipate energy to the next weakest link when they receive a big impact which could be the femur or tibia, however its far quicker and simpler for bone to re-grow than for a joint or ligament complex to have to be fixed. Bone may take weeks to a few months to heal, a knee may never be right again.
The mechanical solution part 2.
The most recent designs of knee braces are no longer bulky heavy or restrictive and most trousers have wider knee compartments to cater for them. Besides this, several brands offer custom braces made or adjusted to your exact specifications so they fit like a glove! The generic knee brace has a number of straps to secure the brace in place for the best comfort possible, hinges to mimic that of the knee joint which provide support to the MCL and LCL and most braces are limited to how much they will flex or extend to protect the knee from being exposed to ligament sprains.
One of the most important things to look for in a pair of knee braces is a patella (knee cap) protector. The patella is a very sensitive part of the knee which covers the ACL and PCL, if the knee suffers a direct impact by a rock, handlebar, foot-peg or a British forces armoured tank (if your name is Wayne Smith) whilst flexed, the PCL is in its most vulnerable position and becomes highly exposed to injury. A patella guard will help prevent this type of injury from occurring. Knee braces not only provide physical protection but can also give a rider more confidence by knowing there is additional support to their knee.
The strengthening solution
The legs are one of the most important tools for controlling the bike and with races lasting 20 minutes+ they need to be strong and have good endurance to avoid fatigue which is where most injuries occur. Good leg strength helps with rider technique and takes the pressure off the arms, take Stefan Everts for example with his famous style of riding on the pegs all the time. He had the biggest set of calfs in the paddock making light work of tough conditions. Hamstring exercises are key to ACL injury prevention. So, Dead-lifts, Nordic curls, and single leg stability training are great exercises for preventing knee injuries and maximizing hamstring strength but approach with caution and seek advice from a qualified exercise professional if you're unsure of how to perform these exercises. You can watch a clip of us training a client following an ACL grade 3 sprain here To book and appointment or to enquire about an injury, get in touch! mail- firstname.lastname@example.org Follow us on twitter @zenanatomy Follow us on Instagram @zen_anatomy